Please Take a Look at My Drains Before I Glue

Users who are viewing this thread


New Member
Reaction score
Scapoose Oregon
Great forum. This is my first post although I've gotten lot's of good information here over the years.

I'm building a one bedroom house for my mom as an accessory structure near our house and on the same septic system. This is the first plumbing project I've done in 5 years and given the crazy price of ABS fittings I was hoping some more experienced plumbers could take a look before I glue it together and have it inspected.

A few assumptions I made based on my reading of our local code:
1) Because I put a two-way cleanout just outside the foundation I don't need a cleanout at the top end of the main horizontal run.
2) The lav, tub, washer, toilet and kitchen sink count as 12 units. A single 2" pipe can vent up to 24 units. Because our house is on the same septic and has two 1.5" vents and a 3" vent, I can use a single 2" vent, combined in the attic for this project.

See any problems in these pictures?

Lav and kitchen sink sharing 1.5" vent. Long trap arm on kitchen sink due to 5" window. Mom wanted a widow over the lav so I brought the vent up at a 45.


Lav and kitchen sink sharing a 2" run, cleanout at end.
lav and kitchen sink.jpg

Main stack, 2" toilet vent. Reduces to 3" and splits into 2" for tub and washer and 2" for lav and kitchen sink.

Washer and tub share a vent. Tub is a wet vent for a few inches below washer trap arm
washer stand pipe.jpg


  • stack tub trap.jpg
    stack tub trap.jpg
    120.9 KB · Views: 40
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks